This invention relates to an artificial lens to be substituted for a natural lens clouded by cataract, said artificial lens being designed to be placed in the space formed by the capsular bag of the lens. This space is produced by the removal of the nucleus of the clouded lens and the cortical remnants.
The implantation technique comprises the maximal dilation of the pupillary aperture by chemical means, making an incision along the upper rim of the cornea, and opening the anterior lens capsule at the level of the upper quadrant by means of a horizontal incision slightly curved towards the eye axis. After expression of the natural lens nucleus a space for receiving the artificial lens is available in the capsular bag which is situated between the anterior and the posterior lens capsule. Subsequently, the collapsed capsular bag is filled with a visco-elastic substance, as is the portion of the capsular bag situated above the incision. Thus an oval gaping hole is produced through which the artificial lens can pass to reach the capsular bag.
The artificial lens has to pass three apertures when being placed in the capsular bag, i.e. the incision along the upper rim of the cornea, the pupillary aperture, which is variable, and the incision in the anterior capsule.
The artificial lens has an optic component of a material (PMMA=polymethyl methacrylate) which is inert in living tissue, as has been proven over the years. This optic portion is smaller than the cataractous lens, so that rentering and anchoring means generally called haptics, (such as a ring, arms, loops, etc.) are required to maintain the lens centrally behind the pupil.
The great flexibility of the arms and ring enables the artificial lens to pass through the comparatively small access aperture of the capsular bag of the lens.